KNOCKING opens the door on Jehovah’s Witnesses. While protecting their own rights, they have won a record number of court cases expanding freedoms for all Americans. In Nazi Germany, they chose the concentration camps over fighting for Hitler. They refuse blood transfusions on religious grounds but support the science of bloodless medicine. They are moral conservatives who stay out of politics and the Culture War. KNOCKING follows two families who stand firm for their often controversial and misunderstood faith. Their stories reveal how one unlikely religion helped to shape history beyond the doorstep.